Blackboard



May 15, 1934. J. F. JOHNSON El AL BLACKBOAFD Filed Feb. 27, 1933 2Sheets-Sheet l y 1934- J. F. JOHNSON El AL 1,958,579

BLACKBOARD Filed Feb. 27, 1933 2 Sheets-Sheet 2 Patented May 15, 1934UNITED STATES PATENT OFFICE BLACKBOARD John F. Johnson and Robert B.Lawton,

Chicago Application February 27, 1933, Serial No. 658,799

7 Claims.

This invention relates in general to blackboards, and is moreparticularly concerned with improvements in a portable blackboardconstruction such as described in our patent No. 1,881,636, issuedOctober 11th, 1932.

In the aforementioned patent, a portable blackboard is described, whichcomprises a plurality of blackboard panels that are swingably mounted ona common pivot, this pivot being removably sup ported in spaced wallbrackets. Locking means are provided by which the several panels may belocked in parallel juxtaposed relation so that the students are unableto ascertain the content of the matter on the panels until such time asthe instructor desires to unlock and open the blackboard panels,whereupon the matter thereon is at once visible.

Further, the arrangement disclosed in the aforementioned patent enablesthe device to be readily moved from one room to another as the occasiondemands, it being only necessary to have a pair of permanently installedsupporting brackets in each room, where it is desired to use the device.

In addition to the advantages and features embraced by our patentedstructure, briefly described above, the present invention seeks toprovide an improved structure, wherein the individual panels are somounted as to be readily detachable, thus enabling the removal of anydesired panel for mounting in another location, as, for example, when itis desired to support one of the panels on an easel or the like, forindividual display of the matter thereon.

A further object of the invention is to provide means whereby theseveral panels may be automatically interlocked, when the panels aremoved into parallel juxtaposed relation, thereby preventing the removalof any panel so long as the panels are locked or otherwise retained inparallel juxtaposed relation.

It is also an object of the present invention to provide a blackboard ofthe character described, wherein the panels may be removed as a unitassembly from their supporting structure, or may be individuallyremoved, as desired.

Other objects andfeatures of the present invention will more fullyappear from the following detail description taken in connection withthe accompanying drawings which illustrate a single embodiment thereofand in which Figure 1 is a front elevation showing a blackboardembracing the features of the present invention applied to a verticalwall structure;

Figure 2 is an enlarged fragmentary plan view showing the individualblackboard panels of the same in angularly disposed relation, takensubstantially on line II-II of Figure 1;

Figure 3 is a similar view showing the individ ual panels in paralleljuxtaposed relation;

Figure 4 is an enlarged fragmentary side elevational view, the panelsbeing in parallel superposed relation and removed as a unit from thewall supporting structure;

Figure 5 is an enlarged fragmentary view partially in cross-section toshow the constructional details of means for detachably mounting one ofthe blackboard panels;

Figure 6 is an enlarged fragmentary sectional view taken through one ofthe hinge supports for one of the blackboard panels, taken substantiallyon line VI-VI of Figure 1.

As shown on the drawings:

As illustrative of the present invention, there is shown in Figure 1 aconventional wall structure 10 having a pair of vertically aligned anglebrackets 11 and 12 secured thereto in spaced relationship in anysuitable manner, as for example, by means of screws 13 which extendthrough each bracket into the wall.

The horizontally disposed legs of these angle brackets are provided withaligned apertures for receiving therethrough a pivot member 14, thispivot member having its lower end threaded for receiving a wing nut 15which coacts with a collar 16 spaced from the lower end of the pivotmember, the Wing nut and collar engaging the opposed sides of thehorizontal leg of the lower angle bracket, whereby the pivot member isretained against longitudinal movement through the bracket.

It will be observed that the'blackboard embraces a plurality ofindividual blackboard panels 17, each panel being composed of asubstantially rectangular frame 18 which is preferably of channel-shapedcross-section and constructed of suitable metallic material such asaluminum, steel and the like. Supported within each frame 18 is a panel19 of blackboard material having its opposed surfaces finished in amanner well known in the art so as to provide suitable writing surfaces.

The frames containing the blackboard panels are respectively connectedto the pivot member 14 in such a manner as to enable the blackboardpanels to be swung in a plane at right angles to the plane of the wallstructure 10, either to a position where in the panels are in paralleljuxtaposed relation as shown in Figure 1, or in angularly disposedrelation as shown in Figure 2.

GOT

Moreover, the connection between each panel and the pivot member is soarranged that the panels may be individually removed from the pivot whendesired.

This connection is accomplished by means of a plurality of pairs ofclips 20 and 21 which are secured to the opposed surfaces of one side ofthe frame 18 as by screws 22. The inner edges of the clips are deflectedas shown at 23 so as to extend around the inner edge of the frame 18,and the outer ends of each pair of clips are deflected towards eachother as shown at 24. It will be observed that the deflected ends 24 areoutwardly spaced from the outer edge of the frame 18 to provide aT-shaped groove: 25 which is adapted to receive a T-shaped end 26 formedat the free end of a hinge member 27 which is pivoted at its other endon the pivot member 14. At the upper end of the T-shaped groove 25, theclipmembers 20 and 21 are inwardly deflected as shown at 28 to form'anabutment against which the T-shaped end of the hinge member will strike,the lower end of the groove being left open so that the T- shaped end ofthe hinge member may be inserted from below.

With the arrangement just described, it will be apparent that ablackboard panel may be quickly and easily secured to: a hinge membersimply. by lowering a panel and letting the T-shaped end of the hingemember pass into the lower end of the T-shaped groove formed by theclips 20 and 21 and move therein until the T-shaped end strikes or abutsthe inwardly turnedends 28 oi the clips, the blackboard panel. beingretained in this position by its inherent weight. To remove a panel itis simply raised until the clips are disengaged.

Although in practice it may be suiflcient inthe smaller devices tosupport each blackboard'panel upon a single hinge member, in the largerdevices, it will be desirable to provide a pair of hinges, these hingesbeing vertically spaced sufiiciently to properly support the larger sizepanel. Irre spective of whether the panels are each mounted on a singlehinge or a pair of spaced. hinges, the hinge members of the outermostpanels, when disposed in. parallel juxtaposed relation, are providedwith angularly disposed portions as illustrated at 29 in order tocompensate for the fact that the panels are in different planes. Exceptfor this offset portion, the hinge members of the outermost panels areof the same construction as those for the innermost panels.

Where each panel is to'be supported on a pair of spaced hinges a pair ofclips as previously described are provided for cooperating with each ofthe hinges. Referring to Figure 5', when the construction is such as tonecessitate the use of two hinges, these hinges are interconnected bymeansof a rod member 30 which serves to maintain at all times the hingesin alignment so as to facilitate the attachment of a panel thereto. Thelowermost hinge member is cons ructed in substantially the same manneras the uppermost hinge member, that is the free end of the hinge memberis provided with a T-shaped end for insertion into the groove defined bythe lower pair of clips. It will be observed, however, that the T-shapedend of the lowermost hinge member is terminated substantially at themid-point between the upper and lower edges of the hinge member, asshown at 31. This construction facilitates the attachment of a panel incases where two hinges are utilized, since the T-shaped end of the upperhinge may be started into the opening between the upper clips and thestraight sided portion of the lower hinge member inserted between theends 24-24 of the lower clips, thereby making it unnecessary to startboth hinges into the clips at the same time.

The upper hinge members of the panels are grouped together on the pivot14, and the lower hinge members likewise are grouped together. The hingemembers of each group are separated by spacing collars as shown at 32 inFigure l, and the. entire group is held against axial movement on thepivot member by means of collars 33 and 34.

Due to this grouping of the hinges and the fact that the hinges areconnected to the respective panels at different levels, the clips of thepanels will successively overlap as shown in Figure 4. It will thereforebe apparent that since a panel must be raised in order to remove it fromits associated hinge members, the panels may all be interlocked againstremoval by the provision of means which will effectively retain thepanel having the uppermost clips secured against removal when the panelsare in parallel juxtaposed relation. For this purpose, a projection orextension 35' is provided on one of the hinge members of the paneladjacent the outermost panel having the uppermost clips thereon, thisprojection being formed with a hook end 36 which will extend over one ofthe clip members and retain the associated panel against removal. Sincethe clips of the respective panels successively overlie each other, allthe panels will be interlocked against removal from their hinge members,when the panels are in parallel juxtaposed position. As soon as thepanels are angularly disposed, the hook end of the extension 35 will notoverlie the clip as previously described, and it will therefore bepossible to remove any panel desired from its hinge members.

In order to enable the panels to be secured in juxtaposed parallelrelation and thereby conceal the matter thereon and also prevent theremoval of any of the panels, a hasp as shown at 3'7 and adapted toreceive a suitable lock, is connected between the outermost panels.

With the panels locked in juxtaposed parallel relation, as shown inFigure 1, the device forms a unit assembly which may be easily movedfrom one location to another. In order to remove the device from thewall brackets, it is only necessary to loosen the wing nut 15, whereuponthe pivot member together with the panels may be raised sufficiently topermit the lower end of the pivot member to be swung out sufficiently toclear the lower wall bracket. The downward movement will then releasethe upper end of the pivot member from the upper bracket, whereupon theen tire unit may be transported to another location and supported in asimilar set of wall brackets.

From the foregoing, it will be apparent that our invention provides animproved portable blackboard which may be folded so as to be easilytransported from one location to another; and which is so constructedthat the individual panels thereof may be individually removed forseparate display of the matter thereon; and in which interlocking andlocking means are provided for locking the panels in parallel superposedrelation, at which time the interlocking means is effective to preventindividual removal of the panels, the interlocking means beingineifective when the panels are swung so as to be in angularly disposedrelation.

Now, it is of course to be understood that although we have described indetail the preferred embodiment of our invention, the invention is notto be thus limited but only insofar as defined by the scope and spiritof the appended claims.

We claim as our invention:

1. In combination, a support, a plurality of individually detachablepanels swingably mounted on said support for movement to paralleljuxtaposed relation and angularly disposed relation, and interlockingmeans operative to secure said panels against detachment when inparallel juxtaposed relation, and release the panels for detachment whenin angularly disposed relation.

2. In combination, a support, a plurality of individually detachablepanels swingably mounted on said support for movement to paralleljuxtaposed relation and angularly disposed relation, interlocking meansoperative to secure said panels against detachment when in paralleljuxtaposed relation, said means being ineffective when the panels are inangularly disposed relation, and means to lock said panels in paralleljuxtaposed relation.

3, In combination, a supporting structure, a blackboard panel, a pair ofvertically spaced hinges connecting said panel to said support forswinging movement, a slip-joint connection between said panel and hingesto enable the panels to be attached and detached, and means to maintainthe movable parts of said hinges against relative swinging movement,when the panel is detached.

4. The combination comprising a supporting structure, a pair ofvertically spaced hinge members pivoted on said support, a blackboardpanel removably connected to the free ends of said members, and a rodspanning said members to retain them against relative pivotal movement,when the panel is removed.

5. A blackboard structure comprising a support, brackets pivoted on saidsupport for swinging movement, a plurality of panels, members removablyconnecting said panels to said brackets, whereby the panels may be movedinto angularly disposed relation and parallel juxtaposed relation, saidmembers being positioned at different levels so as to successivelyoverlap, when the panels are in parallel juxtaposed relation, and meanscarried by one of said brackets having parts arranged for cooperationwith said members so as to retain the panels against removal from thebrackets when the panels are in the last mentioned position.

6. A blackboard structure comprising a support, brackets pivoted on saidsupport for swinging movement, a plurality of panels, members removablyconnecting said panels to said brackets whereby the panels may be movedinto angularly disposed relation and parallel juxtaposed relation, saidmembers being positioned at different levels so as to successivelyoverlap, when the panels are in parallel juxtaposed relation, and aprojecting member on one of said brackets having a deflected endpositioned to overlie the uppermost of said members, when the panels arein the latter position, whereby the panels are retained against removalfrom the brackets.

7. A blackboard structure comprising a support, brackets pivoted on saidsupport for swinging movement, a plurality of panels, said panelsincluding parts removably connecting the panels to said brackets forswinging movement therewith and for interlocking the panels when inparallel juxtaposed relation, and means cooperative with said parts whenthe panels are so disposed to retain the panels against removal from thebrackets.

JOHN F. JOHNSON. ROBERT B. LAWTON.

